Water Quality in The Tibetan Plateau

September 26, 2010

Claude Arpi Blog
September 21, 2010

A very important and interesting PhD thesis has
been published by Xiang Huang on "Water Quality
in The Tibetan Plateau  Chemical Evaluation of
the Headwaters of Four Major Asian Rivers" for
the University of Eastern Finland Faculty of
Science and Forestry under the supervision of
Professor Mika Sillanpää (mika.sillanpaa@uef.fi).

President Hu Jintao who likes to speak of
Scientific Development of China should encourage
more of such studies. Ideally, they should be
undertaken jointly with neighouring States such
as India, Bangladesh or the Mekong countries.

Delhi should push Beijing to work in this
direction. Does not Tibet 'shares' its waters with the entire Asian continent?

Abstract of the PhD thesis of Xiang Huang:

Information on water quality of Asian major
rivers draining Tibetan Plateau is limited, even
though these rivers play a significant role in
lives of more than one third of worlds
population. The purpose of this study was to
contribute to the knowledge of the chemical
quality of these major rivers on the Plateau, to
address major natural factors governing the
spatial variation and to identify possible sources for contamination.

Water samples from a total of 159 sampling sites
along the Yangtze River, Mekong River, Salween
River, and Yarlung Tsangpo (Brahmaputra) in the
Plateau were collected during spring 2006, later
summer 2007 and early autumn 2008. Included in
this work are also a case study of the
drinking-water quality in Lhasa city and a study
of influence of a natural heavy metal enriched
subsurface water and mining activity on the
surface water quality in the central Tibet.
Samples were subjected to a total of 34
physicochemical quality parameters, including
major cations, anions, trace elements, and nutrients.

The solutes in the Tibetan rivers were dominated
by Ca2+ and HCO3 -and that the dissolved matter
is on average the double of that of rivers in
other parts of world. Elevated concentrations of
Na+, Cl-, and SO42-, being largely influenced by
evaporites and drainage from saline
lakes/geothermal waters, are a significant
contributor to these high concentrations of
solutes. Oxidation of sulfides is in addition an
important source for the high SO42-in these
waters. The spatial distributions of these major
solutes in these waters are relatively
homogenous. Multivariable analysis shows that
geology and climate are the major factors
governing the spatial variation. In spite of
alkaline nature of these waters, the average
levels of dissolved trace elements in the Tibetan
rivers are high and their concentrations varied
considerably. Nevertheless, the levels of Ag, Cd,
Co, Cr, and Hg are negligible in all studied waters.

The headwaters of these Asian major rivers in the
Plateau can be considered undisturbed. However,
rapidly increased mining activities pose a high
risk of heavy metal pollution for the local
environment and a potential threat to the downstream water quality.